Victron Energy's BlueSolar PWM Light solar charge controllers are great, incredibly cost-effective little units for maintaining your 12V or 24V Pb battery bank where a full-size MPPT isn't needed. Since these are PWM controllers, the MPPT "vbatt +5V" voltage requirement doesn't apply - as soon as the connected solar panel is generating at least 1V above battery voltage, the controller will start charging! Output voltage is not configurable; 12V battery banks will be charged at 14.2V/13.8V, and 24V battery banks will be charged at 28.4V/27.6V

These are a perfect solution for maintaining a start battery or other small Pb battery bank from a low-wattage solar panel - they will accept up to 28V PV input when charging a 12V battery, or up to 55V PV input when charging a 24V battery.

Features of the BlueSolar PWM Light include:

• Load output with low battery voltage disconnect function.
• Lighting control function, one timer only. 
• Two digit, seven-segment display for quick and easy setting of the load output functionality, including timer setting. 
• Three stage battery charging (bulk, absorption, float), not programmable.
• Load output protected against overload and short circuit.
• Protected against reverse polarity connection of the solar array and/or battery.
• Day/night timing options: see manual for details 

PN (5A): SCC010005000; (10A): SCC010010000